1. Field of the Invention
The present invention relates to a mixing valve in which a main passage through which one fluid passes and one or plural subsidiary passages through which the other fluids pass are connected; and a mixing device using the mixing valve.
2. Description of the Prior Art
In manufacturing fields of, for example, semiconductor devices or chemicals, pure water may be supplied to a predetermined work site through a pipe. In this respect, a mixing valve 110 shown in FIG. 8, such as a manifold valve or the like, is used to mix the pure water and other fluids, such as chemical or the like, appropriately selected in accordance with the operation to be conducted or the product to be manufactured (see, for example, Japanese Patent No. 3207782).
As shown in FIG. 8, in the mixing valve 110, a main passage 113 through which one fluid, e.g., the above pure water (first fluid f1) passes and subsidiary passages 114A, 114B, 114C through which the other fluids, e.g., various chemicals (second fluid f2, third fluid f3, fourth fluid f4) pass are connected via opening/closing valve portions 120A, 120B, 120C to open/close communicating openings 116A, 116B, 116C. Numeral 111 designates a main body block, and numeral 112 designates a valve block.
The subsidiary passages 114A, 114B, 114C are formed beneath the main passage 113. The upper ends thereof open as the communicating openings 116A, 116B, 116C in the main passage 113, and the second, third, fourth fluids f2, f3, f4 passing through the subsidiary passages 114A, 114B, 114C are upwardly supplied to the main passage 113. The communicating openings 116A, 116B, 116C can be opened/closed by the corresponding opening/closing valve portions 120A, 120B, 120C provided in the valve block 112, separately.
The opening/closing valve portions 120A, 120B, 120C are disposed on the communicating openings 116A, 116B, 116C in the main passage 113. Valve bodies 124 are forwardly or backwardly moved across the main passage 113 by air or the like controlled by a controller (not shown), so that the corresponding communicating openings 116A, 116B, 116C are opened/closed inside the main passage 113, to supply or stop supplying the second, third, fourth fluids f2, f3, f4 from the subsidiary passages 114A, 114B, 114C into the main passage 113. Numeral 122 designates pistons of the opening/closing valve portions 120A, 120B, 120C. Numeral 126 designates a diaphragm. Numeral “S” designates a spring to always bias the valve body 124 in the forward direction.
Conventionally, in the mixing valve 110, it is necessary to control the flow rates of the fluids passing through the main passage 113 and the subsidiary passages 114A, 114B, 114C, using outside detecting means such as a flow sensor connected to a pipe of the mixing valve 110.
However, in the above mixing valve, it is inconvenient to dispose detection means in outside passages for a plurality of fluids, and a complicated layout of pipes, wires or the like may cause a trouble. Recently, in such a mixing valve, a more simple structure to control the flow rates of various fluids has been required.